When you think of ecommerce giant Amazon, a company that was founded on selling books online, offering an all-you-can-read book subscription service might seem like a no-brainer. But, so far, nada from Amazon (which, of course, sells just about anything you can think of). Instead, other companies have launched their own subscription services.

That might be about to change. With the inadvertent announcement of an all-you-can read monthly service entitled Kindle Unlimited, Amazon is poised to take aim at companies like Oyster and Scribd, who pioneered the book subscription paradigm but are likely to lose traction under the e-tail giant’s crushing weight.

A webpage touting the new service, which will offer unlimited access to over 600,000 physical titles and thousands of audiobooks for a monthly fee of $9.99, appeared and then was quickly removed from Amazon.com yesterday -- but not before being spotted and cached on a Kindle fan forum page.

According to the page, books on offer will include The Hunger Games series, The Lord of the Rings trilogy, Water for Elephants, The Life of Pi and other bestsellers. However, none of the big-five publishers appear to be participating just yet, notesGigaom, which also was able to pull a promotional video created by Amazon for the initiative.

The books and audiobooks, Amazon says, can be consumed on any device.

Kindle Unlimited could spell disaster for competitors Oyster and Scribd, who were early to the subscription book party but boast fewer titles. Oyster launched last year and offers a library of 500,000 books for $9.95. Scribd, founded in 2007, offers unlimited access to more than 400,000 books for $8.99 a month.

Oyster has raised a total of $17 million -- $14 million most recently from Highland Capital Partners and existing investor the Founders Fund. Scribd has raised $28.5 million, with its most recent round ($13 million) back in 2011.

"Successful companies don't fear competition, but rather embrace it, learn from it and use it to continue to fuel their own innovation, which is exactly what we [intend] to continue doing," Scribd co-founder and CEO Trip Adler told the The Los Angeles Times.

Adding that he was “not surprised” by Amazon’s foray into a Netflix-like business model for books, Oyster co-founder and CEO Eric Stromberg was less convinced of the venture’s potential.

"They have pivoted from transactional to subscription-based in other media,” he said -- referring to Amazon’s Prime programs for videos and music -- “and have had limited success.”

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